Probiotics may be helpful in humanity's fight against heavy metals such as mercury and arsenic.

In a groundbreaking study, Dr. Gregor Reid and his team in Canada used probiotic-enriched yogurt to protect people against absorption of mercury and arsenic from the gastrointestinal tract into the bloodstream.1

According to Reid's study, yogurt infused with Lactobacillus rhamnosus GR-1 protected pregnant women against absorption of mercury by up to 36% and of arsenic by up to 78%. This is the first demonstration in humans of the theory that probiotic microbes can remediate environmental toxins in the gut, according to Reid. His paper was published in mBio (September/October 2014), a journal of the American Society for Microbiology.

Reid says the protective process used by probiotic microbes may be "passive sequestration" whereby the microbes bind to heavy metals in the gut and usher the metals harmlessly out of the body in the stool. By contrast, if heavy metals enter the bloodstream, they can make their way into organs such as the brain, heart, and liver, and do damage.

Reid is a professor of microbiology and immunology and surgery at the University of Western Ontario and also holds an endowed chair in human microbiome and probiotics research at Lawson Health Research Institute. Both institutions are in London, Ontario.

Reid's work is "pioneering" and "fantastic," comments Dr. Benoit Foligne of the Pasteur Institute of Lille, France: "This study confirms, at the clinical level, the promising use against toxins of selected probiotic strains – whether as supplements or as yogurt."

A robust new field is opening up, according to Foligne and Reid – deciphering the mechanisms of probiotics against toxins.2

Dr. Liz Lipski of the Maryland University of Integrative Health, author of Digestive Wellness (2012 4th ed.), comments, "Although the Reid project was a small pilot study of short duration, it opens the door for more research. Using probiotic-rich foods, and supplements, may be a safe and gentle way to prevent absorption of common heavy metals and enhance heavy metal detoxification."

Reid and his team studied 60 pregnant women and 44 children in Mwanza, Tanzania, in the northern part of the African country near Lake Victoria. Many people in the region carry substantial bodily loads of heavy metals, partly because of their diet.3-5 They eat large numbers of silver cyprinid fish, laden with mercury, probably from gold mining in the region, which spews mercury into fish habitat. Mwanzans may also ingest heavy metals from air pollution, says Reid.

Many Mwanzans use mercury to help them find little fragments of gold in streams and rivers (as do millions of people around the world). The mercury binds with gold via a concentration process known as amalgamation. The website www.mercurywatch.org estimates that hundreds of tons of mercury are used annually by small-scale gold prospectors. Minuscule amounts of the metal, just a few grams, can be toxic over wide areas, notes Reid.5

Mwanzan children participating in the Reid study received a daily 9 oz serving of fresh, locally made yogurt, for 25 days. Each serving contained 10 billion colony-forming units of Lactobacillus rhamnosus GR-1. Children in control groups received either whole milk or no intervention. Pregnant women in the study received either daily yogurt for up to 3 months or no yogurt supplement.

Each yogurt serving cost only pennies. "The economics of this approach are promising," Reid says. "I would like to see people around the world empowered to make their own probiotic food – that's totally feasible if we give them access to the probiotic and starter organisms." Refrigeration, he says, need not be an issue. "People can buy milk straight from local farmers, make yogurt themselves, and eat it within days. It's an idea that can transform communities and countries."

He adds, "Humanity is not doing much to reduce mercury, arsenic, and other polluting chemicals, especially in the developing world. We have to do something to combat these toxic compounds. Probiotic therapy appears to be a helpful tactic. Yogurt is inexpensive and is widely accepted."

Heavy metals and metalloids – mercury, arsenic, lead, cadmium, selenium, nickel, copper, etc. – can be toxic or poisonous at relatively low dosages or intakes. The materials have been associated by scientists with many diseases.5-8 They can enter the human body via food, water, air, supplements, vaccines, and dental work. They're dangerous because they tend to bioaccumulate – over time, their concentrations increase in biological organisms.

The US government seeks limits on mercury pollution, but legislation is tied up in the courts.9 Globally, the United Nations is spearheading an antimercury treaty, the Minamata Convention on Mercury, which will come into force when 50 countries have ratified it. So far, about a dozen nations have done this, including the US. Ratification is complex – it means "updating country laws on mercury pollution," says Dr. Joseph DiGangi, a science advisor for the antipollution network IPEN. Critics have blasted the Minamata pact as too weak.

One of the interesting sidelights of the Reid study concerns the silver cyprinid fish widely consumed by Mwanzans. These fish are 2 to 3 inches long. According to many studies, large fish (swordfish, etc.) have a higher concentration of mercury than small ones due to biomagnification.10

Reid and his team were surprised at the level of mercury and arsenic in the small fish of Lake Victoria and are "greatly concerned" about this. Reid comments, "Health practitioners recommend that people – especially pregnant women – avoid large fish because of mercury levels. Our finding about the level of mercury in small fish challenges this recommendation and indicates that it may need to be revised."

Reid, 59, has been a leader in probiotics research since the early 1980s – "since before probiotics were called that," he says. He is the cocreator of Lactobacillus rhamnosus GR-1 and Lactobacillusreuteri RC-14. He has been awarded 28 patents, has published more than 450 peer-reviewed papers, and has delivered 550 presentations to audiences in 53 countries. He served in 2001 as chair of a United Nations/World Health Organization expert panel on probiotics, and was president between 2006 and 2009 of the International Scientific Association for Probiotics and Prebiotics (ISAPP). He remains active today in the ISAPP. He got the idea for the Tanzania study in 2009 and received a grant for the project in 2012 from the Bill and Melinda Gates Foundation.

Reid was born in Barrhead, Scotland, near Glasgow. He had a difficult upbringing. When he was 12 years old, the UK government consolidated educational districts, and he found himself attending class with switchblade-wielding gang members – hooligans, as they were called in Scotland, also known as "neds." Reid was a well-mannered young scholar and was viciously bullied for years. He survived by listening to his parents: "Study," they said. "Work hard."

After high school, he wanted to pursue a career in medicine, but the University of Glasgow School of Medicine declined his application in 1974. He heard later that a number of his peers, with less impressive grades, gained acceptance to the school ahead of him because of their family connections.

His voice tightens as he recalls the unfairness of the admittance system and the bullying of his early years. He seems to have a very strong sense of justice and injustice. "Quite true," he says, "social justice is something I feel strongly about. Justice for people who are treated unfairly, whether by a college, peers, or a big corporation." He endorses the idea of "social business," a concept created by Nobel laureate Muhammad Yunus, who describes it as a "new kind of capitalism that serves humanity's most pressing needs."

Reid earned a microbiology degree with honors in 1978 at the University of Glasgow. At the suggestion of an American friend, he visited Michigan. Life felt different there, he says: "It seemed like opportunity was everywhere." His ambition soared. He won a Rotary International Graduate Scholarship, went to New Zealand for a PhD in microbiology, and did postdoctoral work at the University of Toronto, where, in the early 1980s, he formed a professional alliance with Andrew Bruce, MD, a major figure in the early history of probiotics research.

"Andrew and I were pioneers in probiotics," Reid says. "Some people have forgotten that. It's strange – in science, everyone likes to think that their brilliant idea comes entirely from their brain, from their lab. They forget about the deep sources for their idea" – the historical roots.

"People laughed at us," Reid recalls of his early work with Bruce. "Grant agencies rejected our ideas. We were undaunted!"

Reid says that he and Bruce were the first researchers to "truly target" probiotics for women's health. 11

Probiotic milk was sold in Japan in the 1930s but had no apparent impact in the West. Drs. Barry Goldin and Sherwood Gorbach isolated and commercialized Lactobacillus GG (LGG) with Valio of Finland in 1987. This, says Reid, came "after our team began making breakthroughs." He says, "We were not comfortable commercializing a probiotic without knowing its properties, understanding its effects on humans, and showing it could benefit women. These things took many years."12

Reid says he has fought uphill battles for more than 30 years, urging conventional medicine to embrace probiotics, and advocating reform of governmental regulatory agencies such as the US Food and Drug Administration and Health Canada. He is "rather angry, actually" at the lack of change in "outdated" regulatory systems "designed for potent chemicals but not equipped to deal with bacteria that are part of the human body."

At the same time, he is heartened by the bright-eyed enthusiasm of young people who are getting interested in probiotics. In the last 5 years, he says, the field has gotten "trendy." He gives a lecture about probiotics and the microbiome to second-year microbiology students: "They get totally excited! They envisage so many places where this field could go!"

On a scale of 1 to 10, with 10 being maximum positive impact on human health, Reid rates the impact of probiotics at "8." He explains: "I think beneficial microbes score a '10' – they represent the wider field, inclusive of probiotics. Fecal transplant is an example of using these organisms in a way that is not, strictly speaking, probiotic."

Every day at lunchtime, Reid eats a cup of yogurt. He also takes a daily dose of a product sold in Canada as RepHresh Pro-B, available in the US as Fem-Dophilus – "marketed for women's health," he notes, "but good for anyone's gut."

Next up for Reid and his team: helping people at the poor end of societies gain access to probiotic food, and integrating probiotic concepts into the care of patients who are hospitalized or chronically ill. He predicts, "Over the next 10 years we will see clear proof of the massive impact of beneficial microbes on people's well-being."

Among the key members of the Reid team for the Tanzania study were informaticist Dr. Jeremy P. Burton and microbiome expert Dr. Gregory B. Gloor. Reid's chair at Lawson is endowed with a $6 million contribution by the Dannon Company.